Process of coking liquid or liquefiable bituminous material



Jan. 9, E O, RHODES 1,942,980

PROCESS 0F COKING LIQUID OR LIQUEFIABLE B-ITUMINOUS MATERIAL Filed Dec. 6, 1930 3 Sheets-Sheet l- E, O. RHODES Jan. 9, 1934.

PROCESS OFl COKING LIQUID OR LIQUEFIABLE BITUMINOUS MATERIAL r3 Sheets-Sheet 2 Filed Deo. 6, 1930 EG E E. O. RHODES Jan. 9, 1934.

PROCESS OF COKING LIQUID OR LIQUEFIABLE BITUMINOUS MATERIAL Filed Dec. 6, 1930 s sheets-sheet 3 INVENTOR. I

A TO EY.

Patented Jan. 9, 1934 y 1,942,980 PROCESS oF ooKrNG LIQUID oa Lnlvulslarf1 ABLE BITUMiNoUs MATERIAL Edmund O. Rhodes, Pittsburgh, Pa., assgnor'to American Tar Products Co., Inc., a corporation of Delaware Application December 6, 1930. Serial No. 500,540

4 Claims. (Cl. 2072-32) This invention relates to a process of treating coked but yet fluid or plastic condition while fallbituminous materials and more particularly to ing in the chamber. an improved process of producing coke there- The resulting material is accumulated in this from. plastic condition in a shallow body in the coking 5 In an application of Edmund O. Rhodes, Sechamber to permit coalescence. Further bitumi- 60 rial No. 338,644, led February 9, 1929, a process nous material of such plastic consistency is gradis described in which liquid or liqueable bitumiually added to the said body While at the same nous material is introduced into a highly-heated time proceeding' with -the'coking operation. retort preferably with steamorother gas, and The rate of feeding the fluidbituminous ma coked. The present vinvention is directed to imterial depends largely on the temperature and provementsv in the manner-of introducing liuid pressure of the coking chamber and of the maor liquenablebituminous material into a coking terial being fed. It depends also von the nature of chamber and in the manner of' producing'coke the bituminous matter.. Alcrude tar would be fed therein. The feeding of the material into the in at a lower rate under given conditions than a coking chamber is so conducted that the diiiiculhard pitch for instance. It is desirable that the ties usually encountered in coking 'fluid fbitumirate in each case be such that while the material nous materials, are practically eliminated. is dropping through free space in the coking A In accordancewith the present invention uid chamber, la portion of the Volatile matter therein bituminous material is introduced into a highly is removed before it reaches the bottom of its heated chamberpreferably by means of a spray fall. By such operation enough volatile matter 75 *and preferably with steam. Other gases such as is left so that particles ofthe material -coalesce carbon dioxide, carbon monoxide, hydrogen, before complete coking takes place. methane and nitrogen or mixtures-of the same, The introduction .ofbituminous material is including flue gases, or the gas/ecus products of stopped when the coking chamber is charged to combustionfrom gaseous-liquid or solid-fuels, or the desired level. The coking operation is con- 80 those produced by the carboni'zation of coal, may tinued until the material therein is converted into be used for this purpose but steam is" preferred. a dry or sLubstantiallyfdr-y coke, after which it is Conditions for coking may be further improved removed and the charging operation repeated. by having present in the coking chamber av sup- Coke of excellent structure may be yproduced ply of gases introduced -if desired, by means other by the present process from such materials as than through the sprays for atomizing the bitucoal tars including'coke ovenL tar; oil tars from minous material.` The gases vmay be steam or any Water-gas and oil-gas manufacturing plants; peof tho'se mentioned above or' mixtures of the same troleum oils; pitches or residua from the afore- -including hot combustion gases' or coke oven said materials; and mixtures of these substances.

gases. These gases may be passed through the 'Examples of apparatus which may be em- 0 chamber in any direction and] a- .fresh supply ployed in the process of the present invention A'continuously provided While the bituminous maare shown in the accompanying drawings in terial is being introduced andduring the coking which,`

period or early stages thereof. l A Figure 1 is a vertical sectional View of means 'The gases employed should preferably contain for preheating liquid bituminous matter, and of 95 substantially no free oxygen. Air, foi` instance, al cokingl retort oven-combined -with the said should be excluded as much' as is normally posheating means; f sible during the -charging orcoking operations. Fig. 2 is 'a View `lflrllalew Vertll SeCtIOIl The fluid bituminous material under certain of means for introducing liquid bituminous maconditions maybe heated to any desired temperaterial simultaneously with steam' or othersgas 100 ture before feeding it into the 4coking chamber. into a coking retOIff Oven; It is, incertain cases, advantageous to heat the Fig. 3 is a vertical sectional view taken longimaterial under pressure and feed it into a coking tudinally of a coking retort oven includingv means chamber at a lower pressure. for producing-a' current of gas therethrough;

Extremely good results are'obtained, in any and 105 case, by controlling the rate of feeding the uid Figure 4 is a fragmentary vertical sectional material into the coking chamber. In general, it view taken. transversely of a coke oven chamber may be said that the most satisfactory rate is and showing heating ilues in the side walls of such `that uid bituminous material is converted the said chamber. ,to a substantially semi-coked. or to a partially In the apparatus shown in Fig. `1, bituminous no substantially through the material such as pitch, or tar which has been preferably previously dehydrated, are forced under pressure through a heated bank of tubes 1 by means of a pump 2 and sprayed into a heated coking chamber 3 which is under a lower pressure, for example, substantially atmospheric pressure. A bank of tubes, such as tubes l, is preferable for heating the material although good results may be obtained by substituting a still and pumping tar or pitch from the still to the coking chamber.` n

' Fluid bituminous/material may also be fed from a tank car or other container with or without preheating. When the preheater is not in use, valves 4 and 5 are closed andl material is fed through pipes 6 and '1 to the sprays 8 the valve 9 being open. When material is fed through the preheater, the'valves 4 and 9 are closed and the valve 5 .is open. By opening the valves d and 9 and closing othe valve 5, the material may be by-passed to a vappr release box (not shown) and the unvaporized material conveyed thrpugh the pipes 6 and '7 to the sprays 8. Although the chamber 3 may be any suttable "type of coking retort which maybe heated to the desired temperature preferably by applying the heating medium to substantially its entire outer surface, I have shown, for purposes of illustration, the ordinary type of by-product oven used 30 ovens are built of refractory material, such as silica bricks or the like, and the present process is particularly adapted to their use'. y

Heating flues 3' are provided in the side wal of the oven chamber shown. These flues extend entire height of the walls.

The spraying means 8 are directed downwardly through the openingsin the top of the oven. Valves 10 control the passage of bitumi- ,nous liquidpmaterial through the sprays 8 and 2. Each valve 10 is provided with a spray 8 extending down to thexcoking retort oven 3 through a charging hole 12 and through a suitable opening 13 in the charging hole cover 14, the opening 13 being luted with reclay as shown.

- The spray 8 is provided with an extension l5 passing into the interior of the-valve4=hamber l0 regulated by varying the distance between the valve 4seat 16 and a corresponding valve mem- The valve member 17 is conveniently carried by a hollow spindle 18 which extends into the interior of the extension and which also passes through a gland 1Q and communicates through a valve 20 with the line 11 supplying steam or other gas. By means of a handwheel 21, the Spindle 18 and the valve member 1'? may be raised or lowered, thus opening or closing the orice through which bituminous liquid material discharges from the Aline 7 through the oitake 8 into the coke oven 3. e

A handwheel 22 -is provided and engages the extension 15 and spray 8 by rotation ofl which connection between these two may be severed. Y The spry a may be thereby withdrawn from the Leaaeeo charging hole 12 by means of a suitable handle 23.

The lower end 24 of the oiftake 8 is preferably so shaped that little or none of the bituminous material treated will be sprayed onto the walls of the coking chamber. When the process is carried on in a by-product oven of the long and narrow type, as in case of the usual horizontal oven, the end 2li may be of the shape shown. That is,Y it may be provided with a are, as shown, having a relatively long and narrow opening co-axially disposed with the longitudinal axis of the coking retort oven.

The oven is provided with a suitable vapor outlet which may be in the form of the usual standpipe 25. 'Ihe` vapors pass into a collecting main 26 and are condensed.

In the apparatus shown in'Fig. 3, means. are provided for passing gases through the oven 3 while spraying bituminous material into the oven by means of the sprays 8. For this purpose a pipe 27 is connected to an opening 28 at the end of the c oke4 oven 3 opposite to the end at which the standpipe is placed. In this way the gases fed into the oven through pipe 27 pass through the sprays of bituminous material and carry with 100 them any vaporized matter as they pass through the standpipe 25.

For the purpose of feeding uid bituminous material to the'oven, the sprays 8 may be connected to a loop 29. The fluid bituminous material may be fed continuously through this loop which-may conduct the material from any source and back again. The piping in the loop 29 is shown in an inclined position to provide for drainage of 'the' bituminous material back to its source when the loop is not in use.

When charging with tar, either crude or dehydrated, it may, if desired, be preheated to substantially 700 F. and 'fed under super-atmospheric pressure. The coking chamber for most purposes is heated to a temperature above 1000 F. and preferably from substantially 14.00 nF. to 2200 F.

In order that the coke produced may be easily pushed out, it is necessary to obtain a proper coke structure. This is particularly true with respect to the coke lying adjacent the bottom of the chamber. This coke should be quite dense and rm, because if a'layer of granular coke of appreciable depth is formed=the pushing operation is rendered quite diicult. When charging the coking chamber, therefore, it is advantageous to feed the material rapidly at first after which the rate of feed may be varied if desired. In certain cases it may be desirable to decrease the rate of 13'@ feed substantially, after which the rate may be maintained substantially constant or gradually reduced until the charging is completed.

To' insure the formation of a proper colte structure at the bottom of a'coking chamber, it has been found that the rate of feed' can be initially ias .quite high even td the extent that tar or pitch in a substantially free-owing condition, collects on the bottom of the coking chamber at the beginning of the charging'period. For example, this precaution may be taken 'until the material in the oven has reached a substantial depth of for in- K stance one foot more or less, assuming that the oven is about 40 feet long, l0 feet high and 16 inches wide and the height of the coke produced rected downwardly into the charging holes in a by-product oven. Steam is turned into the sprays and adjusted to about 10 pounds pressure per square inch. Pitch having a melting point of about 260 F. is then admitted to the sprays with the steam at an average rate of about 885 gallons per hour for about 21/2 hours, after which the sprays'are removed and the usual charging hole covers put in place. The coking is continued for about 41/2 hours in which time the coke formed has properly shrunk.

In the above example, the temperature of the oven wall at the start is about 1825" F. and ats the nish about 1895 F.

Example 2,-Pitch having a melting point of about 280 F. is charged without steam into a byproduct oven at the average rate of 920 gallons per hour for about 21/4 hours and the coking completed in about 51/2 hours. the oven wall before charging is about 1760" F. and after pushing out the finished coke the temperature is about 1920 F.

The current required in each of the above cases to start the pushing machine when applied to the coke is about 120 amperes and about 100 amperes after the coke is set in motion.

It has been found in the process of the present invention that the presence of steam or other gaseous substances during the charging and coking operations prevents the breaking down of the bituminous vapors, particularly ino carbon, It is believed that this may be explainedin the following way: Assume that the walls of the coking chamber are heated to a temperature of, say, 1800 F. and that liqueed high melting point pitch for instance is sprayed into the coking chamber at a rate of, say, 400 gallons per hour. Under these conditions it has been found that the vapors that are distilled from the pitch break down to form a considerable amount of carbon in the form of lampblack which leaves the coking chamber with the vapors.

If under these conditions steam or otheru gaseous substances are introduced into the coking chamber, either with the pitch or separately, the formation of lampblack may be diminishedl or n even entirely eliminated. It is. believed that the steam or other gaseous substances accomplish this result by absorbing part of the heat from the coking chamber that otherwise would be transmitted to the bituminous vapors. In this Way the steam or other gaseous substances may be considered as inert materials that exert a cooling effect on the vapors or prevent the superheating of the vapors by absorbing a part of the total available heat.

This is further substan'iated by the fact that if the substance to be coked is charged more rapidly into the coking chamber it is apparently not necessary to employ any steam or other gaseous substances to prevent lampblack formation. To illus'rate this point let us assume that the coking chamber mentioned above with wall temperatures of say 1800 F. is being charged with liquid high melting point pitch at the rate of 400 gallons per hour and that lampblack formation is taking place due to an excessive decomposition of the pitch vapors. If, at such time, steam or other gaseous substances are introduced into the coking chamber the decomposition of the vapors will be lessened or eliminated with consequent reducion or elimination of lampblack formation.

On the other hand, it has been found that if the rate of charging is increased from, say, 400 gallons per hour oto, say, 800 or 1000 gallons per hour the The temperature of I lampblack formation will again be reduced or eliminated for the reason that the higher pitch feed has caused the evolution of a greater quantity of vapors which cannot be superheated to the same extent as the smaller amount of vapor originally present with the same amount of total available hea and a lower rate of charging. Furthermore, with the higher rate of feed the vapors are evolved so rapidly that they are forced out of the coking chamber and therefore subjected to the high temperatures for only a comparatively short time.

In other words, it has been found that when liquid bituminous material is coked the effect produced by the presence of steam or othergas may be obtained by introducing the material into the coking chamber a"2 the proper rate, that is, at such a rate that large volumes of vapors yare formed and yet at such rate that the material deposited in the chamber is of the proper consistency for forming coke of the desired texture.

I'; has been found that the use of steam or other gas, or the employment of a proper rate of feed that will produce similar results, or the employment of a combination of these two methods constitute a very important par: of this process. A coking chamber lined with a refractory material, such as silica brick, is most eiciently operated at rather high temperatures, say above 1600 F. If operated atlow iemperatures, or if operated in such manner that the walls are chilled to low temperatures the life of the walls is considerably shortened by the formation of cracks and the disintegration of the brick.

It has been found that by the employment of steam or other gas or a suitable rate of charging or a combination of the two, high wall temperatures may be employed so that disintegration of the refractory walls is avoided; lampblack formation, due to excessive decomposi'ion of the vapors, may be prevented, and coke of good structure may be produced. These factors, it is believed, determine the success of this method of coking fluid bituminous materials.

The difficulties accompanying the heating of tar or pi'ch'to carbonize the same are well known. In the present process, coke is produced directly from liquid bituminous materials without the difficulties and dangers usually resulting therefrom. There is no trouble from foaming, substantially no formation of lampblack or wall carbon, and substan'ially no burning of bituminous material within the oven.

The coke produced in the manner described is of such texture that when produced in for instance a by-product coke oven such as that de.l scribed' above, it may be pushed out in the convenient manner i hat coke from coal is pushed out.

VVThere is no spalling of the brick lining, or stickby-product oven having side walls with heating 3445 flues extending substantially through the entire4 height vof the walls, which process comprises' heating the sidewalls of the oven to maintain the coking chamber at coking temperatura' charging the bituminous material in a freeiiowing condition into the oven, maintaining the oven above the level of material deposited therein substantially completely filled with vapors from the said bituminous material and at the same time preventing excessive foaming, the said coking of the accumulated material to devola tilize and shrink the coked material, and removing coke from the oven by\a pushing operation.

2. A process of manufacturing coke from bituminous material selected from a group consisting of liquid bituminous material and liqueiiable bituminous material in an externally heated by-product oven having side Walls with heating flues extending substantially through the entire height of the walls, which process comprises heating the side walls of the oven to maintain the coking chamber at coking temperature, charging the bituminous material in a free-owing condition into the oven, separately passing a gaseous medium substantially free from uncombined oxygen through the oven while charging said bituminous material into said oven, the said gaseous medium upon introduction into the oven being at a lower temperature than the temperature of the coke oven, maintaining in the coke oven during the charging period a mixture of said gaseous medium with vapors from the said bituminous material to prevent superheating and decomposition of the vapors to a substantial extent, withdrawing vapors and gases from the oven, collecting the resulting residual material in the oven while simultaneously coking it, continuing the coking of the accumulated material to devolatilize and shrink the coked material, and removing coke from the oven by a pushing operation.

3. A process of manufacturing coke from bituminous material selected from a group consisting of liquid bituminous material and liqueable bituminous material in Ian externally heated by-product oven having side walls with heating lues extending substantially through the entire height of the walls, which process comprises heating the side walls of the oven to maintain the cokbituminous material in a free-flowing condition into the oven, maintaining the oven above the level of material deposited therein substantially completely filled with vaporsnfrom the said bituminous material and at the same time preventing excessive foaming, varying the rate of said charging but introducing the bituminous material during the charging thereof at a rate that eiects the emission of vapors from the oven at a greaterrate than that at which vapors evolved are superheated and decomposed to a substantial extent during their passage through the oven, thereby reducing decomposition and formation of lampblack'; withdrawing vapors from the oven; collecting the resulting residual material in the oven while simultaneously coking it, continuing the coking of the accumulated material to devolatilize and shrink the coked material, and removing coke from the oven by a pushing operation.

4. A process of manufacturing coke from pitch in an externally heated by-product oven having side walls with heating flues extending substantially through the entire height of the walls, which process comprises heating the side walls of the oven to maintain the coking chamber at coking temperature, charging the pitch'in a freeflowing condition into t ve oven, maintaining the oven above the level o material deposited therein substantially completely filled with vapors from the said pitch and at the same time preventing excessive foaming, the said charging being conducted at a rate that eiects the emission of vapors from the oven at a greater rate than that at which vapors evolved'are superheated and decomposed to a substantial extent during their passage through the oven, thereby reducing decomposition and formation of lampblack; withdrawing vapors from the oven; collecting the resulting residual material in the oven while simulta eously coking it, continuing the coking of the lcumulated material to dev olatilize and lshrink t e coked material, and removing coke from the oven by a pushing operation.

EDMUND 0. RHODES.

ing chamber at coking temperature, charging the 

